Anyone keep the stock ecu along with another EMS installed?
 

Presently running this setup....what do you think?

Stock ECU still rund Idle,OMP, fuel pump etc. while aftermarket ecu rins fuel and ignition.

Given the relative cheapness of full replacement ECUs (e.g., PFCs with commanders are now ~$700 new), I can see no reason to do this.

I was going to do this a long time ago with a Buddy Club piggy back. Unfortunately they no longer offer it. If I remember right the tunable software was only available to tuner shops just like the Apexi excel software. It's a shame becuase this was an excellent choice for people that are stuck with strict smog regulations and can't get around them.

i was considering to do this with my microtek Lt-8 cuz it does run the AC...still pondering on it.

this is possible.... i remember reading about a certain black FD that had the stock ECU to manage idle, emissions and either a Microtech, Haltech, or MoTec taking over everything else.

:scratch: My APEXi PFC runs the AC just fine.

some people retain the stock ecu for automatic transmission functions.

No reason to do this on an fd really. Many tuners do this with newer cars that have much more complicated computers than the "Nintendo-like" 8 bit ecu these cars have. The mentality is to have the aftermarket ecu control things like fuel and ignition, while the stock ecu retains control of the other systems and accessories of the car. I can understand why you may want to do this with an auto car, but for the most part it is pointless.

only the auto guys run this setup with the banzai racing harness. this is only to retain the auto trans functions while running a stand alone ecu.

Jeff